/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2008-2012 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package com.sun.mail.util;

import java.io.IOException;
import java.io.OutputStream;
import java.util.logging.Level;

/**
 * Capture output lines and send them to the mail logger.
 */
public class LogOutputStream extends OutputStream {
	protected MailLogger logger;
	protected Level level;

	private int lastb = -1;
	private byte[] buf = new byte[80];
	private int pos = 0;

	/**
	 * Log to the specified logger.
	 */
	public LogOutputStream(MailLogger logger) {
		this.logger = logger;
		this.level = Level.FINEST;
	}

	public void write(int b) throws IOException {
		if (!logger.isLoggable(level))
			return;

		if (b == '\r') {
			logBuf();
		} else if (b == '\n') {
			if (lastb != '\r')
				logBuf();
		} else {
			expandCapacity(1);
			buf[pos++] = (byte) b;
		}
		lastb = b;
	}

	public void write(byte b[]) throws IOException {
		write(b, 0, b.length);
	}

	public void write(byte b[], int off, int len) throws IOException {
		int start = off;

		if (!logger.isLoggable(level))
			return;
		len += off;
		for (int i = start; i < len; i++) {
			if (b[i] == '\r') {
				expandCapacity(i - start);
				System.arraycopy(b, start, buf, pos, i - start);
				pos += i - start;
				logBuf();
				start = i + 1;
			} else if (b[i] == '\n') {
				if (lastb != '\r') {
					expandCapacity(i - start);
					System.arraycopy(b, start, buf, pos, i - start);
					pos += i - start;
					logBuf();
				}
				start = i + 1;
			}
			lastb = b[i];
		}
		if ((len - start) > 0) {
			expandCapacity(len - start);
			System.arraycopy(b, start, buf, pos, len - start);
			pos += len - start;
		}
	}

	/**
	 * Log the specified message.
	 * Can be overridden by subclass to do different logging.
	 */
	protected void log(String msg) {
		logger.log(level, msg);
	}

	/**
	 * Convert the buffer to a string and log it.
	 */
	private void logBuf() {
		String msg = new String(buf, 0, pos);
		pos = 0;
		log(msg);
	}

	/**
	 * Ensure that the buffer can hold at least len bytes
	 * beyond the current position.
	 */
	private void expandCapacity(int len) {
		while (pos + len > buf.length) {
			byte[] nb = new byte[buf.length * 2];
			System.arraycopy(buf, 0, nb, 0, pos);
			buf = nb;
		}
	}
}
